On Thu, Dec 31, 2015 at 09:09:47PM +0200, Michael S. Tsirkin wrote:
> At the moment, xchg on sh only supports 4 and 1 byte values, so using it
> from smp_store_mb means attempts to store a 2 byte value using this
> macro fail.
>
> And happens to be exactly what virtio drivers want to do.
>
> Chec
At the moment, xchg on sh only supports 4 and 1 byte values, so using it
from smp_store_mb means attempts to store a 2 byte value using this
macro fail.
And happens to be exactly what virtio drivers want to do.
Check size and fall back to a slower, but safe, WRITE_ONCE+smp_mb.
Signed-off-by: Mic
